Adefol Big Bore 47mm Cylinder & Chrome Piston Kit for Stihl MS271 MS291 — Complete Overhaul Gaskets & Filters

Adefol's Big Bore 47mm cylinder and chrome piston kit replaces OEM 1141 020 1206 / 1141 020 1201 for Stihl MS271 and MS291 engines, restoring compression and performance with a complete hardware set.

This complete replacement kit is built to match the original equipment dimensions for Stihl MS271, MS271C, MS291 and MS291C chainsaws. It includes the 47mm cylinder and chrome piston plus the consumables and gaskets you need to return the two-stroke engine to dependable running condition after wear or damage. All parts are manufactured to fit OEM tolerances so installation aligns with factory clearances and mounting points.

What parts are included in the Adefol big bore kit?

The kit bundles the core cylinder and piston assembly with the fast-moving consumables often replaced during an overhaul. You get both engine and fuel-related items so fewer separate purchases are required for a full rebuild.

• 1 x 47mm cylinder (old style) matched to the chrome piston
• 1 x chrome piston and rings set sized for 47mm bore
• 1 x air filter screen and 1 x oil filter for maintenance
• Carburetor gaskets (2), fuel pipe, fuel line (2.5x5mm), and fuel filter
• 1 x spark plug and 2 x bar nuts to complete installation

How does this kit fit my Stihl MS271 or MS291 chainsaw?

This replacement is engineered to the OEM part numbers 1141 020 1206 and 1141 020 1201 so bolt patterns, port locations and bore size match factory specifications. That reduces the need for machining, modification, or adapted mounts during rebuilds.

• Direct-fit 47mm bore to match MS271/MS291 engine cases
• Ports and mounting holes align with original Stihl layouts
• Chrome piston surface for wear resistance and smooth operation
• Includes gaskets and seals to restore proper compression

Is installation difficult and what tools are required?

Installation follows standard small-engine cylinder replacement procedures and is straightforward for anyone comfortable with basic chainsaw maintenance. Use common mechanic tools plus a torque wrench to secure fasteners to manufacturer-specified values; if unsure, a technician can complete the job quickly.

• Typical tools: socket set, torque wrench, piston ring compressor or careful ring installation tool
• Follow engine timing and spark plug gap recommendations during reassembly
• Replace gaskets and seals included in the kit to avoid air or fuel leaks
• Allow for a proper break-in period per two-stroke best practices

What performance or longevity differences can I expect?

The kit restores original displacement and compression levels, which helps the saw return to intended torque and throttle response. The chrome-coated piston and matched cylinder bore improve wear resistance versus a worn cast surface, extending time between future overhauls when installed and broken in correctly.

• Restores factory compression for reliable starting and load response
• Chrome piston surface resists scoring and reduces friction
• Complete gasket and filter set reduces leak and contamination risks
• Proper fit minimizes the need for additional machining or shimming

Who is this for: The Adefol Big Bore Cylinder & Piston Kit is made for owners, professional arborists, and repair shops working on Stihl MS271 or MS291 models who need a direct-fit replacement to revive engine performance. It’s ideal when the existing cylinder is scored, compression is low, or you need a consolidated parts pack — including gaskets, filters and hardware — to finish a rebuild without sourcing multiple items separately.